Working tools with wear resistant working surfaces for agricultural implements and other applications

Abstract

A composite working tool, for example a ground engaging tool of an agricultural implement, features a body composed of a first material and an insert composed of a distinct second material of greater hardness than the first material to define wear resistant surfaces of the tool. The tool body has an opening recessed thereinto from an exposed exterior surface fully surrounding the opening on all sides thereof, and the insert is attached to the body in a position at least partially received within the opening, for example by brazing. The increases the wear life of the body and provides greater mounting strength over surface-mounted wear inserts of the prior art.

The invention claimed is: 
     
       1. A composite working tool comprising a body composed of a first material and an insert composed of a distinct second material of greater hardness than the first material to define wear resistant surfaces of the tool, wherein the toot body has an opening recessed thereinto from an exposed exterior surface fully surrounding the opening on all sides thereof, the insert is attached to the body in a position at least partially received within the opening, and the insert is bonded to the body by brazing material disposed between the insert and one or more of a plurality of boundary walls of the opening that surround the insert on all sides thereof. 
     
     
       2. The working tool of  claim 1  wherein a projecting portion of the insert is left outside the opening to extend beyond the exterior surface of the body to define the wear resistant surfaces, which thereby project outward from the body. 
     
     
       3. The working tool of  claim 1  wherein an end of the insert lies flush with the exterior surface of the body. 
     
     
       4. The working tool of  claim 1  wherein the insert is bonded to the body on less than all sides of the insert to leave space between the insert and body on at least one side thereof to accommodate different expansion/contraction rates of different materials among the body, insert and bond. 
     
     
       5. The working tool of  claim 4  wherein the insert is bonded to the body on only one side of the insert. 
     
     
       6. The working tool of  claim 1  wherein the second material is tungsten carbide. 
     
     
       7. The working tool of  claim 6  wherein the first material is a metal other than tungsten carbide. 
     
     
       8. The working tool of  claim 1  wherein the opening is defined by a through-hole passing fully through the body. 
     
     
       9. The working tool of  claim 8  wherein the insert passes fully through the through-hole in order to project from both ends of the through hole to define wear resistant surfaces on opposing sides of the body. 
     
     
       10. The working tool of  claim 1  wherein the insert projects outward from only one side of the body. 
     
     
       11. The working tool of  claim 10  wherein the insert is flush with the exterior surface of the body at a second side of the body opposite the side from which the insert projects. 
     
     
       12. The working tool of  claim 1  wherein the insert is flush with the exterior surface of the body at both ends of the opening. 
     
     
       13. The working tool of  claim 1  wherein the body is that of a ground opening tool of an agricultural implement. 
     
     
       14. The working tool of  claim 13  wherein the ground opening tool has a material delivery channel situated in a position trailing a leading portion of the body in a forward working direction of the agricultural implement to deliver material into a furrow formed by the ground opening tool during use of the agricultural implement, each projecting portion of the insert being situated in a position leading the material delivery material tube in the forward working direction of the agricultural implement. 
     
     
       15. The working tool of  claim 14  wherein the material delivery channel is defined by a material delivery tube that is distinct from the body of the ground opening tool. 
     
     
       16. The working tool of  claim 15  wherein the material delivery tube is attached to the body of the ground opening tool on a trailing side thereof. 
     
     
       17. The working tool of  claim 1  wherein the body has a leading area that leads a remainder of the body in a forward working direction of the tool and the opening is recessed into the body in a direction transverse to the forward working direction at a location trailing the leading area of the body.